Morgan Grenfell, one of the most noble names in the old City of London, has been resurrected by a cheeky former employee, triggering a dispute over the ownership of the company name. Lawyers say the new claimant may be able to keep it.

Companies are increasingly finding that entrepreneurs are trying to take over unused trademarks under rules that put them up for grabs after five years without use, according to Adrian Smith, partner at law firm Simmons & Simmons.

The original Morgan, Grenfell & Co was founded in 1838 and was one of the grand merchant banks along with rivals such as SG Warburg and J Henry Schroder Wagg. However, like most of the other grand City firms, Morgan Grenfell was taken over by a foreign bank seeking instant entry to London after the ‘Big bang’ deregulation of the 1980s.

Morgan Grenfell was acquired by Deutsche Bank in 1990, which, in turn, sold the asset management activities to Aberdeen Asset Management in 2005. The brand is no longer used. However, it has now emerged that fund manager Peter Rutter registered Morgan Grenfell Limited at Companies House on August 28, 2013, along with three related names suitable for asset management activities. He does not have a trademark registration, according to the Intellectual Property Office.

Rutter, who was a graduate trainee at Morgan Grenfell, said he would be keeping the companies for “personal use” and that he had a fondness for the names because they have “a certain history”. He added: “There will be no getting the band back together.”

A spokeswoman for Deutsche Bank said: “We have not had any engagement with Peter Rutter regarding his usage of the brand, neither sold it to him, nor authorised its usage by him. Our legal team will look into Peter Rutter’s usage of the Morgan Grenfell name and respond as appropriate.”

However, Sally Field, intellectual property partner at law firm Bristows, said Deutsche Bank may not be able to claim the rights to the brand if it cannot demonstrate that it has actively used it in the past five years. She said “simply paying a renewal fee” to maintain ownership of the name is insufficient to ensure continued ownership.